Destruction of monster needs statements of support (12)
I believe the answer is:
endorsements
'statements of support' is the definition.
(I've seen this before)
'destruction of monster needs' is the wordplay.
'destruction of' is an anagram indicator.
'monster'+'needs'='monsterneeds'
'monsterneeds' is an anagram of 'ENDORSEMENTS'.
(Other definitions for endorsements that I've seen before include "sanctions" , "Statements of support" , "Records of motoring offences" , "Subscriptions" , "Offences recorded on a licence" .)